vision Flashcards
most of the exposed portion of the eye is covered by a thick structural layer known as the ________
sclera (white of the eye)
*claire is white
____________ contains the actual photoreceptors that tranduce light into electrical information the brain can process
retina
*tina likes to process things (light into electrical signals)
light passes first through the ____________
cornea
_____________ gathers and focuses the incoming light
cornea
*corn is yellow, just like the incoming light that needs to be focused
the front of the eye is divided into the ___________ (which lies in front of the iris) and the ___________ (which lies between the iris and the lens)
anterior chamber
posterior chamber
____________ is the colored part of the ye
iris
*iris is a pretty colored flower
what are the two muscle that make up the iris?
- dilator pupillae
- constrictor pupillae
_______________ opens the pupil under sympathetic stimulation, ____________ constricts the pupil under parasympathetic stimulation
sympathetic, opening = dilator
parasympathetic, closing = constrictor
___________ is connective tissue that surrounds and privides nourishment to the retina
choroid
____________ produces aqueous humor that bathes the front part of the eye before draining into the canal of schlemm
ciliary body
___________ lies right behind the iris and helps control the refraction of the incoming light
lens
*your lenses refract light
the ciliary body is under ____________ control
parasympathetic
contraction of the ciliary muscle pulls on _____________ and chnages the shape of the lens to focus on an image as the distance varies
suspensory ligaments
explain the duplicity theory of vision
the retina contains two kinds of photoreceptors: one specialized for light and dark detection and those specialized for color detection
___________ are used for color vision and to sense fine detail
cones
*think of the shape of a waffle cone, the end is super sharp and pointed (for fine details)
*Cones = Color
T / F - cones are most effective in bright light
true
three forms of cones?
short (blue)
medium (green)
long (red)
*cones are names for the wavelengths at which they have the highest light absorption
___________ are more functional, is highly sensitive to photons, and can be stimulated by light of any color
rods
*only allow sensation for light or dark
*RODuced light
T / F - cones are less useful for detectig fine details because they are spread over a much larger region of the retina
false, rods are less useful
central section of the retina = ?
macula
center region of the macula = ?
fovea
asone moves further away from the fovea, the concentration of ____________ increases while the concentration of ____________ decreases
moving away from the fovea
fovea contains ONLY cones
cones = decrease
rods = increase
__________ is the region of the retina that is devoid of photoreceptors and gives rise to the blind spot
optic disc
rods and cones synapse directly with ____________ cells
bipolar cells
rods and cones synpase with bipolar cells which then synapse with _____________
ganglion cells
what is the purpose of horizontal and amacrine cells?
accentuate slight differences between the visual information in each bipolar cell
*these cells are important for edge detection, as they increase [erception of contrasts
the temporal visual field sitmulates the __________ retinal fibers
nasal
the nasal visual field stimulates the _____________ retinal fibers
temporal
___________ is where the left and right eyes cross paths
optic chaism
some nerve fibers pass to the __________ of the thalamus where they synapse with nerves that then pass through radiations in the temporal and pariteal lobes to the _____________ in the occipital lobe
lateral geniculate nucleus (LGN)
visual cortex
some nerve fibers skip the thalamus and head directly to the ___________ in the midbrain which controls some reflexive responses to visual stimuli and reflexive eye movements
superior colliculi
___________ is the brains ability to analyze information regarding color, form, motion, and depth simultaneously
visual parallel processing
what type of cells detect an object’s form?
parvocellular cells in the LGN
*pervs come in many forms
parvocellular cells have (high / low) spatial recognition and (high / low) temporal resolution
high spatial recognition
low temporal resolution
*only work with stationary or slow moving objects
what type of cells are well suited for detecting motion?
magnocellular cells
magnocellular cells have (high / low) spatial resolution and (high / low) temporal resolution
low spatial resolution
high temporal resolution
*much of the rich detail of an object can no longer be seen once the object is in motion
where are magnocellular cells found?
LGN
what type of cells are responsible for depth perception?
binocular neurons
*binoculars help one see at different depths
where are binocular neurons found?
visual cortex (occipital lobe)
what type of cells associate certain patterns of stimuli with expected behaviors / outcomes?
feature detector cells
where are feature dector cells found?
visual cortex (occipital lobe)
